Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...